#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#include <set>
#include <map>
typedef long long ll;
const ll INF = 1e9;
using namespace std;
int link[500005], sz[500005];
set<int>adj[500005];
int find(int x) {
while (x != link[x]) x = link[x];
return x;
}
void unite(int a, int b) {
a = find(a);
b = find(b);
if (a == b) return;
if (a != b) {
if (sz[a] < sz[b]) swap(a, b);
sz[a] += sz[b];
link[b] = a;
}
}
void solve()
{
int n, m; cin >> n >> m;
for (int i = 1; i <= n; i++) { link[i] = i; sz[i] = 1; }
vector<pair<int, int>>a;
for (int i = 1; i <= m; i++) {
int u, v; cin >> u >> v; char c; cin >> c;
if (find(u) != find(v) && c == 'T') {
unite(u, v);
}
else {
a.push_back({ u, v });
}
}
for (auto x : a) {
int u = find(x.first); int v = find(x.second);
if (u != v) {
adj[u].insert(v);
adj[v].insert(u);
}
}
int cc = 0;
for (int i = 1; i <= n; i++) {
if (find(i) == i)++cc;
}
int ans = 0;
for (int i = 1; i <= n; i++) {
if (find(i) == i && adj[i].size() == cc - 1)ans += sz[i];
}
cout << ans << "\n";
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
int t = 1;// cin >> t;
while (t--) solve();
return 0;
}
